Giant Duodenal Brunneroma: Report of a Rare Case and Review of the Literature

Introduction

Brunneroma of the duodenum constitutes a rare group of benign proliferating lesions, most of which remain asymptomatic. The Brunner’s glands are acinotubular glands located in the mucosa and the submucosa of the duodenum, though they may also be found in the proximal jejunum [1]. The number of the Brunner’s glands gradually decreases along the length of the duodenum. Their primary role is to protect the proximal duodenum from the acidity of the enzymes secreted from the stomach through their bicarbonate secretion, which neutralizes the former.

Brunneromas are usually benign, described as a proliferative lesion in the duodenum and are characterized by its mucin-containing glands [2]. However, Brunner’s adenomas (hamartomas) are usually large lesions in the duodenum’s submucosal layer, comprising a combination of cystic glands and muscle proliferation [3–5].

Among the most prominent symptoms, bleeding, sequential anemia, and signs of gastrointestinal tract obstruction prevail [5–9]. This type of tumor’s prognosis is excellent if treated promptly and radically. Therefore, they must be differentiated from other tumors, especially malignancies. Given the benign nature of these tumors, any other pathology causing similar symptoms must be excluded before implementing the appropriate treatment. The therapeutic approach may vary, contingent on the site and the size of the tumors, from conservative therapy to radical excision of the tumor [10–12].

Case Report

A 39-year-old man with no known medical history presented to the Emergency Department with a 2-month history of persisting melena and intermittent epigastric pain. Clinically, he appeared weak, with pallor and cold extremities. After initial resuscitation and stabilization with intravenous (IV) fluids, complete blood laboratory investigations were performed, confirming the anemia (Hb 11.7g/dL, MCV 87fL). A computed tomography (CT) scan of the thorax and abdomen with oral and IV contrast revealed a filiform stenotic tumor (Figure 1, arrow) of Pars II of Duodenum (maximal 8 cm), with pronounced endoluminal extension with partial missing differentiability form Caput pancreas. Given the CT scan results, without being able to exclude the presence of a malignancy, it was decided that the patient should be referred to our department for further investigation and surgical management.

Following admission to our department, a gastro-duodenal endoscopy was performed. The endoscopy verified the presence of a polypoid mass in the second part of the duodenum, from which biopsies were taken (Figure 2A and 2B, cross). Furthermore, antral gastritis was diagnosed, while a Helicobacter pylori infection was excluded. The histopathological examination revealed a hypertrophic Brunner gland polyp. The CEA and CA 19-9 values were within normal limits.

After the case was discussed with the multidisciplinary meeting (MDT) board, the patient was taken to the operating room, where he underwent duodenotomy via laparotomy, resection of the giant Brunneroma, and cholecystectomy. Given the tumor’s proximity to the ampulla of Vater, a small-caliber tube was inserted through the cystic duct during the operation to ensure its integrity. After resection of the tumor, the duodenum was closed primarily using monofilament absorbable sutures in 2 layers. The resected tumor was 7.5×5.1×4.1cm in size (Figure 3). The histopathologic analysis of the resected tumor confirmed the initial diagnosis of Brunneroma, covered with normal duodenum-mucosa and light chronic inflammation, without any signs of malignancy, in agreement with the preoperative biopsy result.

Postoperatively, he was stable but needed to be transfused with 1 blood unit, and the rest of his recovery was uncomplicated. He was discharged 11 days after admission. Based on the results above, the MDT board suggested an endoscopic follow-up within 3 months after the operation, which showed no disease recurrence or other pathological findings.

Discussion

Even though the small intestine accounts for approximately 2/3 of the entire length of the bowel, tumors arising from it are rare. Since their initial description, approximately 200 case reports have been published in the literature [13]. Brunneromas account for 5–10% of all small bowel tumors diagnosed, occurring mainly during the 5th and 6th decade of life [14]. In terms of the tumor’s site, Levine et al [15] have suggested that approximately 70% of them are found in the duodenum bulb (segment I). Moreover, a correlation has been observed between the tumor’s size and site, since the more proximal the tumor is, the larger it is expected to be. In our case, the tumors transitioned from the duodenum bulb to segment II. Given the histological findings of the resected tumor in the present case, the diagnosis of Brunneroma was established based on the absence of any elements of muscle or fat tissue. As far as the epidemiology of the benign lesions of the Brunner’s glands is concerned, Brunner’s gland hamartomata is found in approximately 0.007% of patients who undergo a routine esophagogastroduodenoscopy, whereas hyperplasia in detected in only 0.03% [16,17].

Concerning the etiology and the pathogenesis of these benign lesions, it is thought that the leading cause of the pathogenesis of Brunneromas is embryonic dysplasia [6]. It is suggested that the proliferation of the Brunner glands, which leads to the tumor’s clinical manifestation, could result from increased acid secretion. This hypothesis is based on the physiological function of “anti-acid” secretion glands [18]. Kaplan et al showed in 1969 that hyperchlorhydria was diagnosed in only 45% of the studied patients [19]. About 71% of all Brunneromas are associated with H. pylori infection [20]. In our case, no signs of H. pylori infection were found. However, the patient was diagnosed with gastritis of the antrum based on the endoscopic findings, which could support the theory of hyperacidity. The actual stimuli are yet to be found, but signs of chronic inflammatory alterations were found in our specimen.

The clinical manifestation of Brunneromas includes a vast spectrum of clinical signs. They may present from an asymptomatic course to fresh bleeding, melena, or iron deficiency [6,7], the most extreme being upper gastrointestinal tract obstruction [5,8,9]. The differential diagnosis should include leiomyomas, adenomas, lipomas, GISTs, leiomyosarcomas, and periampullary pancreas tumors [21].

Endoscopic ultrasonography has been proven to be one of the most useful diagnostic procedures preceding surgery due to the possible evaluation of the lesions’ origin, extent, and vascularity [22,23]. Moreover, it can be combined with endoscopic biopsies, improving diagnostic accuracy [24]. CT scans are more useful in identifying the nature of the tumor than in determining the relation of the tumor to the adjacent structures and possible indirect radiological indication of malignancy [25–27].

Regarding the therapeutic options, small tumors can be treated endoscopically. This approach offers the advantages of low invasiveness, safety, low costs, and shorter hospitalization [10]. On the other hand, for larger lesions or those sited in the second segment of the duodenum and peripapillary, the surgical approach is a more feasible therapeutic option [11] so that the contingency of atypia or malignancy can be permanently excluded. The appropriate surgical therapy for the lesions is yet to be established. Recurrence is rare after radical endoscopic or surgical treatment [12].

Conclusions

The Brunneroma should be considered as a differential diagnosis for any tumorous lesions of the upper gastrointestinal tract. Accurate and prompt diagnosis can prevent development of obstructive symptoms, bleeding, or intussusception. An interdisciplinary approach should be considered to provide optimal therapy for the patient.